Remember that stool samples have to be REALLY fresh! Meaning, if you happen to get one, put it in the fridge.
With snakes, its hard to get/keep a fresh enough one. Shouldn't matter to much though, my vet was able to get enough "matter" with a long q-tip looking thing, and that way it was very fresh.
Protozoans are sometimes difficult enough to find in a sample, so the fresher the better.
Definitely take all records with you, not only the ones from Corny, but also all new animals you have gotten within the last year/6 month or so, and if there is anything "off" with any of those.
Most likely it is actually nothing at all. Or if anything, something easy to treat.
But since you are actually going to a good reptile vet, this is your chance to ask about everything and to have all the tests done that are possible on a live animal. Plus discuss any questions, concerns and possibilities.
I'm crossing fingers and toes that its just one of those things, like males taking a feeding break or breeding season or something along those lines.